The idea is to abstraction PDO itself. Developers don’t need to know about the implementation if it is either a PDO or simple PHP database interaction code. (To get a better understanding you might want to look into this – http://www.phpclasses.org/package/6535-PHP-Access-different-types-of-SQL-database.html.) Just follow the implementation in the sample class. It might not look like what I have mentioned but in case your team is big it might look true.